Fluid-actuated fastener-applying machine



5 sheets-sheet 1 l 77 v 5f/ r 73 a3 84 F/G L. M. OSBORNE FLUIDj-ACTUATEDFASTENER-APPLYING MACHINE if -..f mmwmmmwmmm w oct. 7, 1958 Filed Oct.17. 1955 Oct. 7, 1958 v L, M. osBoRNE 2,854,953

FLUlD-ACTUATED FASTENER-APPLYING MACHINE Oct. 7, 1958 L. M. osBoRNEFLUID-ACTUATED FAsTENER-APPLYING MACHINE Filed Oct. 17. 1955 3Sheets-Sheet 3 1.14 tislmnlllllllll INVENTOR:

United States Patent O LUID-ACTUATED FASTEN ER-APPLYIN G MACHINE LloydM. Qshorne, Burbank, Calif. Application October 17, 1955, Serial No.540,921

Claims. (Cl. 121-3) This invention relates generally tofastener-applying implements and machines and is concerned moreparticularly with a duid-actuated device for driving staples and similarfastenersto secure lathing to building studs, roofing material to roofboards, and for various other uses.

Various forms of fluid-actuated, staple-driving hammers and similarimplements are currently in use for securing sundry materials andarticles together or for fastening different objects against surfaces.Such contrivances usually include a casing having a throat at one enddefining a passageway, a staple magazine for containing a supply ofstaples in stick form, a staple feeding means for'advancing the staplessuccessively from the magazine into the passageway, and a driver bladereciprocable in the casing and adapted, when moved through a workingstroke, to shear the leading staple from the stick or refill and driveit through the throat and into the work against which the throat end ofthe casing of the device is held. The motive power for actuating thedriver blade may consist of a piston reciprocable in the cylinder of thecasing and to which the driver blade is attached. The casing, or ahandle portion thereof, is provided with air passage means through whichcompressed air is introduced into an end of the casing to act againstthe piston so as to operate the latter through a working stroke, valvemeans being employed for controlling the ingress of the air into thecylinder.

In certain machines, the valve and air passage means are so arrangedthat the compressed air is applied against either side of the piston toselectively actuate the staple driver through working and returnstrokes, the valve means being of a type permitting exhaust of the airfrom either end of the cylinder as air is `admitted to the other endthereof. In other similar machines, the piston and staple driver areactuated pneumatically only through the working stroke, a coil springdisposed within one end of the cylinder and engaging the piston beingoperative to return the piston to its inoperative position andsimultaneously expel the air from the other end of the cylinder. Ineither case, the rate of movement of the piston and driver is dependentupon the permissible rate of discharge of the air from the cylinderthrough the valve. For this reason, the reciprocatory speed of thedriver, and consequently the number of staples driven during a giventime, are necessarily limited.

lt has also been determined that where the air is introduced into theend of the cylinder, from which the air was previously exhausted duringthe return stroke of the piston and driver, the pressure of thecompressible air must increase to a value capable of exerting suft`1-cient force against the piston to actuate the latter through its workingstroke. Consequently, there exists a certain time lag between theopening of the control valve and the actual start of movement of thepiston and driver. Moreover, at the start of the operative stroke of thepiston, the movement is relatively slow and as the force 0f the airpressure increases, the movement is gradually ice accelerated. As aresult of this condition, instantaneous driving force of maximumamplit'ude is not attained and the impact force of the staple beingdriven may be such that the staple is not driven completely into thework.

I have determined that in order to drive the staple with the impactnecessary to embed its legs lirmly in the work, the driver must beoperated rapidly and with considerable driving force. Stated anotherway, the air must be applied at full pressure against a considerableelective area of the piston, the pressure lirst building up quickly andbeing suddenly released against the piston t-o actuate the driverrapidly through a working stro-ke. The present improvedfastener-applying implement is designed to carry out this highlydesirable operation in a practical and etlcient manner.

One object of the present invention is to provide a fluid-actuated,fastener-applying implement or device which is capable of drivingfasteners into wood and other materials with suliicient impact topositively embed the staple legs entirely in the work while utilizing arelatively low fluid pressure as the motive power.

Another object of the invention is to provide a fastenerapplyingimplement, of the character referred to, which embodies a cylinder, apiston slidable in the cylinder, a driver blade carried by the pistonand reciprocable in a throat provided at the working end of thecylinder, said driver being operable to successively shear staples froma stick thereof fed intermittently into the throat from a magazineextending normal to the plane of the throat, the implement furtherincluding means for applying fluid pressure against the piston toactuate the same through a driving stroke, and means operable to returnthe piston and the driver to their inoperative positions following eachactuation of the device.

In accordance with another important object and feature of theinvention, the device or implement is so designed that the actuatingpiston is subjected to the total fluid pressure instantaneously uponopening of a valve-controlled inlet orice and this effects instantaneousmovement of the driver through its operative stroke.

Another object of the invention is to provide a fluidactuatedfastener-applying implement which includes a main valve having a headexposed to uid pressure within a chamber at all times, the valve headbeing of a crosssectional area such that the fluid pressure actingthereagainst normally creates a force of insufficient magnitude upon thevalve to activate the piston through its operative stroke. However, whenthe valve is opened to establish fluid flow from the chamber into thecylinder to impinge against the piston, the entire end area of thepiston is subjected to the uid pressure to be propelled rapidly througha fastener-driving stroke.

Another object of the invention is to provide an irnplement of the typeindicated in which the upper end of the main lluid chamber is defined bya disc connected to the stem of the main valve to be movable axiallydownwardly therewith. By this provision, the volumetric capacity of themain chamber is reduced as the valve is opened to join the chamber inuid communication with the upper end of the cylinder, so that loss offluid pressure through expansion of the chamber, which would temporarilyreduce the force applied against the piston, is prevented. As a resultof this novel structure, the piston is subjected to a sudden downwardthrust to overcome inertia so as to propel the driver downwardly with apositive and rapid action.

Aonther object of the invention is to provide in an implement of theclass specied, fluid-actuated means for opening the main valve.According to the present concept, this meanms consists of avalve-actuating plunger slidable vertically in an axial bore in the stemof the main valve element and having a lower, rounded end engageableagainst a seat or annular shoulder formed at the lower end of the bore.By this means, when the plunger is forced downwardly, its lower endengages the seat or shoulder to force the main valve element downwardlyto open the valve. The valve-actuating means also includes an auxiliarypiston slidable in the casing and carried at the upper end of theplunger, the space existing between the auxiliary piston and the uppereind of the casing constituting an auxiliary chamber for receivingpressure iiuid from the supply line when a manually-operable controlvalve is opened. Thus, when the auxiliary piston is subjected to thefluid pressure throughout its large area, it acts through the plunger tounseat the main valve. The area of the auxiliary piston is considerablygreater than the area of the valve head exposed to fiuid pressure withinthe main chamber and as the valve element is initially engaged by theplunger, the forces applied against the plunger by the auxiliary pistonand directly against the valve head by the fiuid pressure within themain chamber combine to impart a sudden downward thrust which opens thevalve with a rapid action.

Another object of the invention is to provide an implement of the typeindicated having means embodied therein by which the air initiallyintroduced into the actuating cylinder to perform a staple-drivingoperation is exhausted at a rapid rate when the control valve isreleased, so that instantaneous return of the piston and driver toinoperative position is effected. In accordance with the presentconcept, this means includes the stem of the main valve and thevalve-actuating plunger, the latter being of non-circularcross-sectional shape and defining, with the bore of the valve stem inwhich it fits, air exhaust passages through which the air may escapefrom the actuating cylinder into the auxiliary chamber and thence to theatmosphere through an exhaust port provided in the wall of the casingand communicating with the auxiliary chamber.

Another object of the invention is to provide a fluidactuatedfastener-applying implement or machine of alternative construction inwhich a diaphragm is employed in lieu of the disc, said diaphragm havingits peripheral portion fixed relative to the casing and its centralportion connected to the stem of the main valve. In this modifiedstructure, the diaphragm divides the upper portion into a lower, mainchamber in which fiuid pressure is maintained, and an upper, auxiliarychamber into which pressure fluid is introduced through the controlvalve, flexing of the diaphragm in response to introduction of the fiuidinto said auxiliary chamber acting to depress and open the main valve soas to allow passage of the pressure fiuid into the actuating cylinder toactuate the piston and driver through a working stroke. In thisalternative implement, a reciprocable, part-tubular plunger is arrangedfor sliding movement in the bore of the valve stem for engaging aninternal seat within the stem, said plunger having a shoulder exposed tothe fluid pressure within the auxiliary chamber to effect seating of theplunger. Exhaust of the pressure fluid from the auxiliary chambercreates an unbalanced pressure condition wherein the diaphragm isrestored to its unffexed state to close the main valve whereupon thefluid pressure existing within the cylinder unseats the plunger to allowexhausting of the uid through the valve stem and the plunger to theatmosphere by way of an exhaust port provided in the casing, so as toallow return of the piston and driver to inoperative position under theinfluence of the return spring. i

Another object of the invention is to provide an alternative controlvalve means which is electrically actuatedV to openand close the fluidinlet and outlet passages leading 1nto and from the auxiliary chamber ofthe fastener-applying device. In accordance with the invention,

the valve has an actuating solenoid which is energized in response toengagement of a switch-closing plunger against the work into which afastener is to be driven.

Another object of the invention is to provide a control valve means offurther modified structure which is particularly adapted forincorporation in a fastener-applying device of the general characterreferred to above, said control valve means including a casing structureproviding upper and lower compartments separated by an annular seatelement engageable by a movable valve member in the form of a ball, theupper compartment being in fluid communication with the main pressurefiuid supply as existing within the main chamber of the implement whilethe lower compartment is connected to the upper, auxiliary chamber by afluid passage. A tubular valve-actuating element is slidable in thecasing of the device and is adapted, when moved in one direction, toengage and unseat said ball so as to allow passage of the pressure fluidfrom the supply to the upper compartment, thence through the seatelement to the lower compartment and into the auxiliary chamber by wayof said fiuid passage. Upon return movement of the actuating pistonV anddriver, due to exhausting of the pressure fluid from the cylinder, theiiuid pressure acts against pistonlike heads or anges on thevalve-actuating element to move the latter in a reverse direction, thisaction causing the ball to seat, thus preventing ingress of pressurefluid into the auxiliary chamber but allowing exhaust of the fluid fromsaid auxiliary chamber through the tubular actuating element to theatmosphere. According to the present concept, the tubular actuatingelement may be slid to valve-opening position by mechanical means, suchas a presser foot carried at its lower end and engageable against thework. In another embodiment, the element may be slid by manual means,such as a trigger pivoted to the casing and operatively connected to theelement.

Another important object of the invention is to provide an improvedcontrol means for use generally in controlling the introduction ofpressure uid into a cornpartment, such as an actuating cylinder, saidmeans including a movable valve having a head for opening and closing anorifice leading into said compartment, means for applying fiuid pressurebetween a fixed area surrounding the orifice and one side of a portionof the valve member of larger pressure area than that of said head so asto normally move the valve member in a direction to seat its head in theorifice, said valve member having a tubular stem, and a plunger slidablein the valve stem and having a pressure area operative, when exposed tofiuid pressure at the other side of said portion of the valve member, toeffect movement of the plunger in a direction to cause an end of theplunger to engage a seat within the valve stem to close the latter,fiuid pressure applied against said pressure area of the plunger andagainst said other side of said portion serving to move the valve memberin a direction to open said orifice to admit pressure fiuid into saidcompartment to perform work, release of fluid pressure from against saidother side of said portion and the pressure area of said plunger firstallowing unseating of the plunger and then movement of the valve memberin a direction to seat its said head under the effect of fluid pressureexisting within said compartment, the valve stem and plunger togetherdefining a fiuid exhaust passage through which pressure fiuid canexhaust from the compartment when the plunger is unseated. Thus, thefiuid control means is, in effect, a valve within a valve wherein theinner valve is first seated and the two valves next moved in unison in afirst direction to open an orifice, after which the inner valve-is firstmoved in the opposite direction to unseated position prior to movementof the outer valve in said opposite direction to close said orifice.

Further objects of the invention will appear from the followingdescription and from the drawings which are intended for the purpose ofillustration only, and in which: v

Fig. 1 is a vertical sectional view through one form of thefluid-actuated, fastener-driving implement;

Fig. 2 is a plan view of the valve member taken on line 2-2 of Fig. 1;

Figs. 3, 4 and 5 are Small-scale views, similar to Fig. 1, showing7 therelation of the piston-actuating means during successive stages of thestaple-driving operation, these views of being of a more or lessdiagrammatic nature; v

Fig. 6 is a view similar to Fig. 1, illustrating a fastener-applyingimplement of a modified form;

Figs. 7 and 8 are cross-sectional views, taken respectively on lines 7-7and 8 8 of Fig. 6;

Fig. 9 is a view similar to Fig. l, showing a further alternativeconstruction of the device;

Fig. 10 is a vertical sectional view, taken on line 10-10 of Fig. 9; f

Fig. 11 is a cross-sectional View, taken on line 11-11 of Fig. 9; and

Fig. 12 is a fragmentary, vertical sectional View of a portion of theimplement illustraed in Fig. 9, showing an alternative means foractuating the control valve.

The Huid-actuated, fastener-applying mechanism of the present inventionis adapted for hydraulic or pneumatic operation. Consequently, the termspneumatic, airactuated, air-pressure etc., as employed in the followingdescription are to be construed as covering broadly a Huid-actuatedmeans and motive fluid, whether the latter be of a liquid or gaseousnature. In addition, while the device as disclosed herein is designedfor driving staples into the work, it will be apparent that themechanism may be so constructed that it may apply fasteners of othertypes, the term staple therefore being used in a general sense to coverall fasteners capable of being driven into the work. As will be laternoted, while the fastener-applying means covered by the presentinvention is herein illustrated as embodied in a portable implement ortool, such means may be incorporated in a more or less stationarymachine and the terms implement, device and tooL are intended to includesuch machines.

Referring rst to Figs. 1 to 5, the fastener-applying implement of thisinvention may take substantially the form therein illustrated. In thistypical example, the implement includes a vertical casing 20 whichcomprises lower and upper tubular sections 21 and 22 welded together asindicated at 24 and an annular partition or valve seat element 23 isinterposed therebetween. The upper end of the top section 22 is closedby an upper cap or end plate 25, secured in place by screws 26. In asimilar manner, the lower end of the bottom section 21 is closed by alower cap or end plate 27 fastened in place by screws 2S. This lower endplate 27 has a depending projection 30 which provides a throat throughwhich staples are driven into the work by means to be later described indetail, the cap 27 and its throat portion 36 having a vertical groove 31of rectangular cross-section, the length and width of this groove beingsubstantially equal to the length and thickness of the cross-bar of astaple S to be driven through the throat. The rearward side of thethroat portion 30 is recessed at 32 to receive the forward end of astaple magazine 33 having an elongated bar or core 34 along which thestick of staples S is advanced into the throat by means of aconventional, spring-actuated staple pusher 35. The forward end of themagazine 33 may be attached to the throat by means of screws 36.

Suitably fastened against a side of the upper casing section 22 is ahandle or hand grip 40 by which the implement can be supported in a handof the person operating the same, a sealing pad 41 being interposedbetween the casing and the handle to provide an air-tight joint.

The seat element 23 is provided with a central opening or orice 44which, as shown is tapered to provide a valve seat. A valve member 45 ofthe tappet type has a tapered head 46 adapted to seat upwardly againstthe valve seat 44. The member 45 has an upwardly directed, tubular stem47 having a reduced portion providing an annular shoulder 48 againstwhich a movable partition disc 49 is held by means of a nut 50 screwedonto the upper threaded extremity of the stern. The valve member 45 isadapted to slide vertically within the upper casing section 22, downwardmovement of the member being limited by engagement of the movable disc49 against an annular shoulder 51 within the upper section. An G-ring 52is tted within a peripheral groove in the disc 49. It is to be observedthat the valve member 4S has an axial bore 53 of circularlcross-sectional shape (Fig. 2). The lower end of the valve member 45 isilared inwardly at the bore 53 to provide a seat 55 for a plunger 56which, as shown in Fig. 2, is of non-circular cross-sectional shape, forexample, square. The plunger 56 has an upper reduced end 57 upon whichan auxiliary piston 58 is held, this piston carrying an O-ring 59 at itsperiphery.

The' disc 49 and auxiliary piston 58 divide the upper portion of thecasing 20 into a main air chamber 60 between the valve seat element 23and the disc 49, an air exhaust chamber 61 between the disc 49 and theauxiliary piston 58, and an auxiliary cylinder 62 between the piston 58and the upper end cap 25. The internal area of the casing 20 between thevalve seat element 23 and the lower end cap 27 constitutes a main aircylinder 63. A first air inlet port 66 is provided in the wall of theupper casing section 22 and communicates with the air chamber 60. Asecond air inlet port 67 is likewise provided in said wall, this portcommunicating with the auxiliary or secondary cylinder 62. An airexhaust port 68, also in the wall, is employed for directing air fromthe auxiliary chamber 61 to the atmosphere.

The hand grip 40 is provided with a main air inlet passage 70 forreceiving air from a compressed air tank,

through a hose 71. The passage 70 leads to a bore 72 in whicha valvecasing 73 is disposed. A rst air passage branch 74 extends from the bore72 to the air inlet port 66, thus bypassing the valve casing so thatwhen pressure air is supplied to the main passage 70, the main chamber6d is charged with the same.

A valve element 75 is slidable within the casing 73 and normally isurged upwardly by means of a coil spring 76 engaging against anactuating button 77 at the upper end of the element. Air enters thelower end of the valve casing 73 through a hole 78. The valve element'75 has an L-shaped passage 79 which, when the element is depressed,aligns with a hole 80 in the wall of the casing 73, the hole S0communicating with a second air passage branch S1 leading to thesecondary air inlet port 67 so as to cause the pressure air to enter thesecondary cylinder 62. When the valve element '75 is released to beprojected upwardly by the spring 76, a groove 83 in its peripheryprovides a flow passage between the hole 80 and a second hole 84connected to an air exhaust passage 85' provided in the hand grip 40 andleading to the atmosphere.

Slidable in the main cylinder 63 is a main actuating piston whichcarries a staple-driver blade 91 which is slidable in the throat 31, thepiston having an O-type sealing ring 92 engageable with the wall of thecylinder. A coil spring 93 having its end portions engaging in recessesin the piston 90 and end cap 27 normally is operative to force thepiston upwardly to its inoperative position.

Assuming that the parts of the staple-driving implement are in thepositions illustrated in Figs. 1 and 3, pressure air is present in thechamber 60. This pressure acts` between the seat element 23 and the disc49 of the valve member 45 to normally maintain the latter in its upperposition, the effective area of the head 46 exposed to the air pressurebeing relatively small. Since the valve element 75 is in its upperposition, flow of pressure air from the passage 70 to the secondarycylinder 62 is prevented and the implement thus is inactive. With thelower end of the driver 91 located above the core 34, the staple pusher35 urges the stick of staples S forwardly to locate the leading staplewithin the throat, directly below the driver 91. i

To apply a staple S to the work, the operator holds the implement by thehand grip 40 and places the lower end of the throat element 30 againstthe work. The valve element 75 is next depressed to align its flowpassage 79 with the hole 80, passage 81 and inlet port 67 so as to causeintroduction of the pressure air into the secondary or auxiliarycylinder 62. The air, acting between the cap 25 and piston 58, propelsthe latter downwardly. Thus, the plunger 56 is forced downwardly tocause its lower rounded end to engage the seat 55 so as to close thebore 53. The combined fluid pressure forces acting against the piston Sand against the valve head 46 is sufficient to unseat the valve head(Fig. 4) to effect rapid ow of the pressure uid from the chamber 60 intothe cylinder 63. At this instant, the air pressure within the chamber 60is applied against the full area of the main piston 90. This force issuliicient to overpower the spring 93 and propel the main piston 90downwardly at a very fast rate of movement. Thus, the driver 91 iscaused to shear the leading staple S from the strip and drive it throughthe throat 31 and into the work with great impact. Movement of the valvehead 46 to open position is limited by engagement of the disc 49 againstthe shoulder 51.

When the valve button 77 is released following the driving of a staple,the valve element 75 returns to the position shown in Fig. l so that theair within the secondary cylinder 62 exhausts to the atmosphere by wayof the port 67, passage 81, hole 80, groove S3, hole 84 and passage S5.Such exhaust of air allows upward movement of the secondary piston 58and this is immediately affected to cause the air to be exhausted fromthe secondary cylinder due to the uid pressure within the main cylinder63 acting against the lower end of the plunger 56 exposed thereto (Fig.5). Since the piston 5S no longer functions to force the valve member 45downwardly, the liuid pressure within the chamber 60, acting between thepartition 23 and the disc 49 now restores the valve member 45 to itsinitial position to close the orifice 44, this action being augmented byuid pressure within the main cylinder 63 acting upwardly against thevalve head 46. Referring again to Figure 5, it, will be noted that thevalve 46 is first closed and thereafter further compression of the airabove the piston 90 causes the plunger 56 to become unseated. This, inturn, raises the piston 58 to the position shown in Figure l. Uponunseating of the plunger 56, the pressure fluid within the main cylinder63 is caused to exhaust through. the passages defined between thecylindrical bore 53 and the at sides of the plunger 56. The fluidexhausts into the chamber 61 and thence to the atmosphere through theport 68. While such exhausting of the uid is relatively fast to effectquick return of the piston 90, this action is cushioned by the fluidexhausting from the auxiliary cylinder 62. Consequently, recoil of theimplement is practically nil.

It will be observed from the above that the driving action of the piston90, as effected by the application of pressure air thereagainst, is veryrapid so that the staple is driven with great impact and its legs arefully embedded in the work. Due to theV large effective areas involved,air of relatively low pressure can be utilized to operate the valve 45and piston 90. Also, because of the rapid response of the parts toactuation of the control valve 75, the implement can be operated inrapid succession to apply the staples, the rate of such application ofthe staples to the work being limited onlyY by the ability of theoperator to actuatenthe control valve 75. It is also to be noted thatthe d evice can be operated in any position so that it is adaptedfor'uise in fastening lathe or sheet material to/verti'cal, as wellashorizontal, building surfaces.

Referring now to Figs. 6 to 8 of the drawings, the present inventionalso contemplates an implement of alternative structure.` This modifieddevice includes a cylindrical casing 100, to the upper and lower ends ofwhich are applied end caps 101 and 102. Substantially midway between itsends, the cylinder carries a cup-shaped element 103, the lower,transverse end portion 104 of which provides a partition or valve seatportion, a segmental orifice 105 in the partition having a taperedportion providing a valve seat 106.

Disposed within theiupper end of the casing 100 is a sleeve 107.Interposed between this sleeve and the upper end of the element 103 isthe peripheral portion of a diaphragm 110. As shown, the central portionof the diaphragm is held between a pair of rings 111 retained against aperipheral shoulder 112 on the tubular valve stem 113 of a valve member114, a clamping ring 115 on the stem holding the rings 111 in place. Atits lower end, the valve member 114 has a tappet-like valve head 116engageable against the seat 106. The valve stem 113 has a bore 117 whichis enlarged intermediate the upper and lower ends of the member 114,thus providing a conical valve seat 118.

A plunger 120 has an enlarged flange portion 121 slidable in the upperend portion of the stem 113, this flange carrying an 0-ring 122 forsealing between the flange and the bore of the stem. Below the ange 121,the plunger 120 is of less diameter than the upper end of the bore inthe stern, thus providing an air exhaust passage 125. The plunger 120has an axial bore 126 which terminates above the lower end of theplunger. A transverse hole 127 in the plunger 120 establishes fluidcommunication between the interior of the stem 113 and the bore 126. Theupper end of the plunger 120 is Slidable in a vertical hole 12S formedin the upper end cap 101. A radial air exhaust passage or port 129communicates between the hole 12S and the atmosphere. An O-ring 130seals the clearance between the hole 128 and the plunger 120.

The valve seat portion 104, diaphragm 110, end caps 101 and 102 define,with the walls of the casing 100, an actuating cylinder 131, an airchamber 132 and an auxiliary or secondary air cylinder 133.

Slidable in the cylinder 131 is a main piston 135, normally urgedupwardly to the position shown in Fig. 6 by means of the spring 136.Fluid pressure could be employed in lieu of the spring 136. As in thepreviouslydescribed embodiment, the piston 135 carries a staple driverblade 138 which is Slidable in a vertical staple groove formed in thethroat portion 139 of the lower end cap 102, into which the staples Sare fed successively into position beneath the driver.

A handle or hand grip 142 is secured against a side of the upper portionof the casing 100 and has an air inlet passage 143 to which pressure airis supplied by an air hose 144 connected to a suitable source ofcompressed air. The passage 143 leads to a bore 145, the air thenpassing through a branch passage 146 and an inlet port 147 into thechamber 132.

A control valve 150 has a casing or sleeve 151 forced into the bore 145,the sleeve having a hole 152 in its lower closed end and a transversehole 153 thereabove. A plunger 155 is Slidable in the sleeve 151 and hasa peripheral groove 156 and an L-shaped air passage 157. A coil spring158 normally maintains the plunger in its raised, valve-closingposition. At one side of the sleeve 151, the hole 153 is in fluidcommunication with the secondary cylinder 133 by reason of a branchpassage 159 and air inlet port 160. At the other side of the sleeve 9151, the hole 153 communicates with the atmosphere by way of anairexhaust passage 161.

The control valve plunger 155 normally is held in the positionillustrated in Fig. 6 to effect exhaust of air from the cylinder 133, byreason of the spring 158. A solenoid 163 is operative, when energized,to depress the valve plunger 155 so as to align the passage 157 thereofwith the branch passage 159 and thus connect the cylinder 133 to thesource of compressed air.

The solenoid 163 is connected in an electrical circuit including thewires 164 and 165 adapted for connection to a service outlet. Connectedin series with the solenoid 163 are spring contact elements 166 and 167mounted, by means of dielectric discs 168, within a recess in the lowerend cap 102, the contact elements being of U-shape to extend around thedriver 138 (Fig. 8). Slidable in a vertical hole 169 in the throat 139is an actuator pin or presser rod 170, the lower end of which normallyprojects downwardly below the throat to engage the work into which astaple is to be driven. The upper end of the rod 170 is positioned toengage the lower contact element 167.

When it is desired to drive a staple, the implement is placed such thatthe throat extension engages the work. The presser rod A170 thus isforced upwardly to tlex the contact element 167 against the contactelement 166 to close the circuit to the solenoid 163 so as to energizethe latter. As a result of such energization, the control valve plunger155 is depressed to establish flow of pressure air from the passage 143,through the hole 152, passage 157, hole 153, branch passage 159and inletport 160 into the cylinder 133. Pressure air thus introduced into thesecondary cylinder 133 rst acts against the exposed end of the ange 121of the plunger 120 to force the lower end of the latter into engagementwith the conical seat 118. The diaphragm 110 then is ilexed downwardly,as indicated by the broken lines in Fig. 6, so as to force the valvemember downwardly. With the valve 116 thus unseated, the pressure airflows rapidly from the chamber 132 into the main cylinder to be applieddirectly against the full pressure area of the piston 135 so as topropel the latter and driver 138 downwardly to shear the leading stapleS from the strip or stick and drive the same into the work.

Following the driving of the staple into the work, pressure of theimplement against the work is relieved to allow projection of thepresser rod 170 under the spring tension of the contact element 167.This action eifects separation of the contact elements so as to open thecircuit to the solenoid to deenergize the latter, whereupon the spring158 raises the valve plunger 155 to disalign the passages 157 and 159and align the exhaust groove 156 with the transverse hole 153. By thisaction, the cylinder 133 is connected to the exhaust passage andatmosphere so as to allow exhaust of air from this cylinder. The fluidpressure within the actuating cylinder is then applied against the lowerend of the plunger 120 to raise the latter from the conical seat 118.Unseating of the plunger 120 establishes air flow from the main cylinder131 to atmosphere by way of the hole 27, bore 126 and passage 129.Simultaneously, the pressure within the chamber 132 is exerted againstthe diaphragm 110 to move the valve member 114 into position to seat itshead 116. The piston 135 comes to rest adjacent the valve head 116 tolocate the lower end of the driver 170 above the plane of the staplestick to allow advancement of another staple into the groove 169 inposition to be subsequently driven.

Referring now to Figs. 9 to l2, the instant invention furthercontemplates a modified fastener-applying device in which the controlvalve means is actuated mechanically in response to engagement of thedevice against the work. This modiled structure includes a cylindricalcasing 200, the upper and lower ends of which are closed by end caps 201and 202. The casing 200 has a partition 203 provided with a central holeor valve orice 204.

The casing 200 is formed with a hollow handle or hand grip 205, theinterior of which receives pressure air from a source through the mediumof a hose 206.

A tappet-type valve member 210 is slidable within the upper end of thecasing 200 and has a conical head 211 at its lower end engageable withinthe orifice 204 to close the same. The valve member 210 hasa bore 212which is enlarged intermediate its ends, thus providing a conical valveseat 213. The member 210 has a piston portion 215 slidable in a bore 216in the upper end cap 201, downward sliding movement of the member beinglimited by a stop ring 217. The end caps 201 and 202, the partition 203and secondary piston 215 define with the casing 200 a main actuatingcylinder 220, an air cham ber 221 and a secondary or auxiliary cylinder222.

A main piston 225 is slidable in the main cylinder 220 and carries thestaple driver 226. A spring 227 nor mally is operable to maintain thepiston and driver in the elevated position shown in Fig. 9.

An air inlet port 229 in the casing 220 connects the air chamber 221with the interior of the handle 20S. The upper end cap 201 is providedwith an air exhaust port 228.

Slidable in the upper end of the valve member 210 is a plunger 235having an annular shoulder 236 exposed within the auxiliary cylinder222. The upper end of this plunger is slidable in a hole 237 in the endcap 201. The plunger 235 has a conical lower end 238 engageable withseat 213. The plunger has a bore 239 terminating above its lower conicalend, and a transverse hole 240, the interior of the valve member 210thus being in communication with the atmosphere by way of the hole 240,bore 239 and passage 228.

The device of Figs. 9 to 12 embodies a novel and ingenious control valvemeans which is constructed and arranged as next described.. As shown inFig. 9, the upper end cap 201 is provided with a lateral extension 245formed with an air chamber 246. Below the chamber 246, the casing 200has three vertically aligned bosses 248, 249 and 250. The upper boss 248has a bore 252 and a compartment 253 arranged directly below the chamber246. A sleeve or seat element 255 is located within the compartment 253and has an orifice 256 communicating with theV chamber 246 andcompartment 253. A valving element, in the form of a ball 25S isdisposed within the chamber 246 and normally rests upon the sleeve 255to seal the orice 256 against passage of air from the chamber 246 to thecompartment 253. A tirst air passage 262 in the boss 248 extends betweenthe chamber 221 and the valve chamber 246. A second air passage 263extends between the compartment 253 and the auxiliary cylinder 222(Figs. 9 and ll).

A combined valve-actuating and air-exhaust tube 265 is slidablevertically in the bosses 248, 249 and 250, the upper end of this tubebeing located within the compartment 253, directly below thc ball 258.As shown in Figs. 9 and l0, the tube 265 has piston-like heads 267 and268 which are slidable respectively in the bore 252 in the boss 243 anda bearing hole 269 in the boss 249. These heads have O-ring seals 270.The boss 249 has an annular shoulder 271 against which the head 268engages to limit the downward sliding movement of the tube 265.

Carried at the lower end of the tube 265 is a sleeve 273 which has abore 274 provided with a closed lower end. A transverse hole 275 in thetube communicates between the bore 274 and atmosphere. Fitted within aslot 276 in the lower end of the sleeve 273 is the upper end of avalve-actuating element or bar 278. As shown in Fig. 10, the bar 278 hasa lateral extension or foot 279 which extends beneath the staplemagazine 230 at a level slightly below the lower end of the throatextension 281 of the lower cap 202, in position to engage against thework into which a staple is to be driven.

With the implement connected to the source of compressed air and withthe parts in the positions illustrated in Fig. 9, thev implement isready for use. To drive a staple S into the work, the implement is heldin a hand of the operator by means of the hand grip 205. It will beapparent that at this time air pressure exists within the hand grip, inthe inlet port 229 and the chamber 2214. Such pressure is also presentin the passage 262 and valve chamber 246.

To drive a staple, the throat portion 281 is directed toward the workand during this movement the presser foot 279 is engaged against thework to force the sleeve 273 and tube 265 upwardly as shown in Fig. l0.During this action, the upper end of the tube 265 engages and lifts theball 253 from the seat 255 to first seal the exhaust tube 265, whereuponthe pressure air in the valve chamber 246 flows rapidly into thecompartment 253 and passage 263 and thence into the auxiliary cylinder222 to act against the shoulder 236 of the plunger 235 to depress thelatter into engagement with the conical seat 213 so as to close the bore212 of the valve member 210. Simultaneously, the piston 215 is subjectedto the air pressure. The effective areas of the piston 215 and the valvehead 211 exposed to the fluid pressure are such that the valve member210 is depressed rapidly so as to open the orifice 204. Thus, pressureair is admitted to the upper end of the main cylinder 220 to act againstthe upper end area of the piston 225 so as to rapidly propel the pistonand staple driver downwardly and thus drive a staple S through thethroat and into the work. The piston 225 preferably carries a resilientbumper pad 283 for cushioning the impact of the piston against the lowerend cap 202. Downward movement of the valve member 210 is limited byengagement of the auxiliary piston 215 against the stop ring 217.

After the staple has been applied to the work, manual force of theimplement against the work is relieved to allow the valve-operating barto descend. This latter action is effected by reason of the air pressurewithin the chamber 246 acting against the ball 258 to depress the tube265. The compartment 253 thus is sealed from the pressure chamber 246.At this juncture, the air pressure existing within the cylinder 222,passage 263 and compartment 253 acts against the head 267 to forciblyslide the tube 265 downwardly until the head 263 engages the stopshoulder 271. The air within the cylnder 222 thus may exhaust to theatmosphere by way of the tube 265 and holes 275.

With the valve member 216 thus free to slide upwardly, the pressure airwithin the upper end of the main cylinder 220 exerts an upward thrustagainst the lower end of the plunger 23S to raise the latter relative tothe valve member 21?. With the plunger 235 thus unseated, the air passesinto the valve member 210 and thence exhausts through the hole 240 andbore 239 to the atmosphere by way of the exhaust port 22S. Fluidpressure within the chamber 221, acting against the piston 215, restoresthe valve member 210 to initial position to seal the orifice 204. Themain piston 225 and the staple driver 226 connected thereto returnupwardly to inoperative position under the influence of the spring 227.Such upward movement of the piston 225 is limited by engagement of thepiston against a stop ring 285. Return movement of the plunger 235 islimited by engagement thereof against the bottom of the hole 237 in theend cap 201. Such return of the parts to initial position is automatic,as heretofore explained in connection with the structure of Figures land 4.

lt is within the concept of the instant invention to actuate the valvemeans 265, 258 manually by means of the trigger finger 362i? shown inFig. 12. The operating 'finger 350 has a forked end 301 pivoted on a pin502 held in a lug 393 forming part of the casing 200. The trigger 399has slots in the sides of the forked end for receiving pin 305 carriedby the sleeve 273. As

12 will be apparent, upward pivotal movement of the trigger effectsupward sliding movement of the tube 265 to unseat the ball 258 and toclose the exhaust tube.

It will be observed from the foregoing that the present inventionprovides a fastener-applying implement or machine which is fluidactuated and which is positive and extremely rapid in operation. Unlikeother fluid-'actuated devices of this general type, the pressure fluidis introduced into the actuating cylinder in response to actuation of avalve member which normally is in position to close a fluid orificeleading to the actuating cylinder. As a feature of improvement, thelvalve member normally is maintained seated in response to fluidpressure present in a chamber of the device at all times, this pressureacting between a fixed area within the casing and a disc, diaphragm orother part operatively connected to the valve member and having apressure area considerably larger than that of the head of the valvemember, fluid pressure exerted against the head and said part beingsufficient to open the valve member to admit pressure fluid into theactuating cylinder. According to the invention, the valve member has afluid exhaust passage thereinthis passage being closed prior toactuation of the valve member to its open position, the means forclosing the exhaust passage being in the nature of a plunger having afirst end adapted to engage a seat within the exhaust passage to sealthe latter, and a second end adapted to be exposed to the full fluidpressure to move the plunger to passage-closing position. By thisarrangement of parts, when fluid pressure against the said part of thevalve member and plunger and this fluid a1- lowed to exhaust from thecasing, the pressure fluid previ-V ously introduced into the actuatingcylinder acts to unseat the plunger to open the fluid exhaust passagethrough the valve member so as to allow rapid exhausting of the fluidfrom the cylinder. Since the valve member meets no resistance to itsreturn movement to orificeclosing position, the pressure fluidcontinuously applied against its said disc or other part restores thevalve member automatically to initial position to close said orifice. Itis thus seen that the double valve means for controlling introduction ofpressure fluid into, and exhausting of the same from, the actuatingcylinder functions to first close the exhaust passage and then actuatethe valve member to open position so as to inject the pressure fluidinto the cylinder; and following actuation of the device through aworking stroke the exhaust passage is first opened and the valve memberthen moved to closed position, this being a feature which produces a newand unexpected result not attainable by the use of conven-A tionalcontrols wherein the exhaust passage is opened following closing of thevalve member.

As another feature of improvement, in the present device the exhaustpassage of the valve member is opened during exhausting of the pressurefluid employed to seat the plunger and open the valve member.Consequently, the exhausting head of fluid serves as a cushion or bufferto absorb shock so that recoil of the device is avoided. The device thusmay be operated in rapid succession without undue shock, to drive thefasteners firmly into the work. Also, due to the relatively largeeffective pressure areas involved, fluid pressure of lower value thanheretofore employed in similar devices may be utilized to advantage.

The device has been herein described as of a portable hand ty-pe but itwill be apparent that the mechanism may be embodied in a stationarymachine, in which case the hand grip may be dispensed with and thecontrol valve means and inlet, outlet fluid passages incorporated in themachine housing or in fluid lines leading to and from the variouschambers. It is also within the present concept to utilize fluidpressure, in lieu of the return spring, for returning the main piston toinoperative position in which case the pressure fluid will be introducedinto and exhausted from, the lower end of the actuating 13 cylinder intimed sequence with the valve member and other elements. The invention-further contemplates a device or machine in which the driver, throatand other parts are designed with a view toward driving nails or thelike into the work.

In accordance with the provisions of the patent statutes, I have hereindescribed the principle of the invention, together with several forms ofconstruction of the device. It will be apparent, however, that Variousmodifications might be made in the structure, without departing from thespirit or scope of the invention, as defined in the appended claims.

l claim as my invention:

1. In a fluid-actuated fastener-applying device, a closed, hollow casinglhaving a throat at one end, a partition in said `casing having a valveorifice; a piston reciprocable in said casing between said partition andsaid throat; a fastener-driver blade carried by `said piston, a valvemember having a head at the side of said partition adjacent said pistonfor seating in said orifice; a first fluid pressure means normallyoperative to maintain said head so seated; plunger means movable in saidcasing and engageable with said valve member; a second fluid pressuremeans operable to move said plunger means in a direction to engage saidvalve member and unseat said valve head; control valve means associatedwith said second fluid pressure means for controlling application offluid pressure against said plunger means, unseating of said valve headeffecting application of the first pressure fluid against said piston toactuate the latter through a working stroke, inactivation of said secondfluid pressure means allowing seating of said valve head; and means forapplying a force against said, piston to return the same to inoperativeposition adjacent said partition.

2. In a fluid-actuated fastener-applying device, a closed hollow casinghaving a throat at one end, a partition in said casing having a valveorifice; a piston reciprocable in said casing between said partition andsaid throat, a fastener-driver blade carried by said piston, a valvemember having a head at the side of said partition adjacent said pistonfor seating in said orifice; a first fluid pressure means normallyoperative to maintain said head so seated; plunger means movable in saidcasing and engageable with said valve member; auxiliary means having asealing engagement with and movable relative to the end 'of said casingopposite to its said throat end, said means being operatively connectedto said valve member and having a fluid pressure area in excess of thefluid pressure area of said valve head; a second fluid pressure meansoperable to move said auxiliary means and said plunger means in adirection to unseat said valve head; control means associated with saidsecond fluid pressure means for controlling application of fluidpressure against said auxiliary means and said plunger means, unseatingof said valve head effecting application of the first pressure fluidagainst said piston to actuate the latter through a working stroke,inactivation of said second fluid pressure means allowing seating ofsaid valve head; and means for applying a force against said piston toreturn the same to inoperative position adjacent said partition.

3. In a fluid-actuated fastener-applying device, a closed, hollow casinghaving a throat at one end; partition means in said casing and providedwith an orifice, the portion of the casing at one side of the partitionmeans constituting a main actuating cylinder anda portion of the casingat the other side thereof providing a fluid chamber; a pistonreciprocable in said main cylinder and carrying a fastener-drivermovable in said throat; fluid' passage means for introducing pressurefluid into said chamber and continuously maintaining fluid pressuretherein; a valve member movable axially in said chamber and having avalve head, said head being disposed in said main cylinder and normallyurged into said orifice to close the same under the influence of thepressure fluidV in said chamber, force of the fluid pressure in saidchamber 14 t acting against the area of said valve head exposed theretoin said orifice being insuflicient to unseat said valve head;valve-actuating plunger means within said casing engageable against saidvalve member and having a portion adapted to be exposed to fluidpressure; fluid passage means for applying fluid pressure against saidportion so as to cause said plunger means to actuate said valve memberin a direction to unseat its said head and allow flow of the pressurefluid from said chamber into said main cylinder, pressure fluid thenapplied against the end area of the piston exposed thereto actuating thepiston through an operative stroke; control valve means selectivelyoperative to effect application of the pressure fluid against saidportion of said plunger means to actuate the same and to effect exhaustof said pressure fluid following such actuation; exhaust passage meansembodied in said valve member, plunger means and said casing byrwhichthe pressure fluid in said main cylinder can exhaust to atmosphere inresponse to return movement of said main piston; and means for applyinga force against said piston to return the same to inoperative positionadjacent said partition.

4. In a fluid-actuated fastener-applying device, a closed, hollow casinghaving a throat at one end, partition means in said casing and providedwith an orifice, the portion of the casing at one side of thepartitionmeans constituting a main actuating cylinder and a portion ofthe casing at the other side thereof providing a fluid chamber; a pistonreciprocable in said main cylinder and carrying a fastener-drivermovable in said throat; fluid passage means by which pressure fluid isintroduced into and continuously maintained within said chamber; a valvemember movable axially in said chamber and having a valve head disposedin said main cylinder, the fluid pressure in said chamber normallyurging said valve member in a direction to maintain its said head insaid orifice to close the same, force of the fluid pressure in saidchamber acting against the area of said valve head exposed thereto insaid orifice being insuicient to unseat said valve head; Valve-actuatingplunger means within said casing engageable against said valve memberand having a portion adapted to be exposed to fluid pressure;

fluid passage means for applying fluid pressure against.

said portion so as to cause said plunger means to actuate said valvemember in a direction to unseat its said head and allow flow of thepressure fluid from said chamber into said main cylinder, pressure fluidthen applied against the end area of the piston exposed theretoactuating the piston through an operative stroke; control valve meansselectively operative to effect application of the pressure fluidagainst said portion of said plunger means to actuate the same and toeffect exhaust of said pressure fluid following such actuation; exhaustpassage means embodied in said valve member, plunger means and saidcasing by which the pressure fluid in said main cylinder can exhaust toatmosphere in response to return movement of said main piston; and meansfor applying a force against said piston to return the same toinoperative position adjacent said partition means.

5. In a fluid-actuated fastener-applying device, a closed, hollow casinghaving a throat at one end, partition means in said casing and providedwith an orifice, the portion of the casing at one side of the partitionmeans constituting a main actuating cylinder and a portion of the casingat the other side thereof providing a fluid chamber; apiston'reciprocable in said main cylinder and carrying afastener-driverrmovable in said throat; fluid passage means by whichpressure fluid is introduced into and continuously maintained withinsaid chamber; a valve member movable axially in said chamber and havinga valve head disposed in said main cylinder; fluid pressure-actuatedmeans normally operative to urge said valve member in a direction tomaintain its said head across said orifice to close the same, force ofthe fluid pressure in said chamber acting against the area of said valvehead exposed thereto in said orice being insufficient to unseat saidvalve head; valve-actuating plunger means Within said casing engageableagainst said valve member and having a portion adapted to be exposed tofluid pressure; Huid passage means for applying uid pressure againstsaid portion so as to cause said plunger means to actuate said valvemember in a direction to unseat its said head and allow llow of thepressure Huid from said chamber into said main cylinder, pressure uidthen applied against the end area of the piston exposed theretoactuating the piston through an operative stroke; control valve meansselectively operative to etect application of the pressure fluid againstsaid portion of said plunger means to actuate the same and to effectexhaust of said pressure fluid following such actuation, said valvemember having an axial bore and an internal shoulder engageable by saidplunger means to rst close said bore and thereafter move said valvemember to valve-opening position, relief of uid pressure from againstsaid portion of said plunger means allowing movement of said plungermeans from 15 said shoulder under the influence of the pressure fluid insaid main cylinder acting thereagainst so as to allow exhaust of saidpressure fluid from said main cylinder through said bore, said casinghaving an exhaust port communicating with said bore, and to allow returnof said valve member to initial position under the influence of thefluid pressure within said chamber; and means for applying a forceagainst said piston to return the same to inoperative position adjacentsaid partition means.

References Cited in the le of this patent UNITED STATES PATENTS2,320,340 Appton June l, 1943 15 2,338,127 McAndrews Ian. 4, 19442,400,330 Allen May 14, 1946 2,459,456 Rockwell -,l Jan. 18, 19492,585,939 Juilfs Feb. 19, 1952 2,585,940 Iuilfs Feb. 19, 1952 202,729,198 FacCOu Ian. 3, 1956

